thorvg/src/savers/gif/tvgGifSaver.cpp

/*
 * Copyright (c) 2023 - 2025 the ThorVG project. All rights reserved.

 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:

 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <cstring>
#include <memory>
#include "tvgStr.h"
#include "tvgGifEncoder.h"
#include "tvgGifSaver.h"

/************************************************************************/
/* Internal Class Implementation                                        */
/************************************************************************/

void GifSaver::run(unsigned tid)
{
    auto canvas = unique_ptr<SwCanvas>(SwCanvas::gen());
    if (!canvas) return;

    auto w = static_cast<uint32_t>(vsize[0]);
    auto h = static_cast<uint32_t>(vsize[1]);

    buffer = tvg::realloc<uint32_t*>(buffer, sizeof(uint32_t) * w * h);
    canvas->target(buffer, w, w, h, ColorSpace::ABGR8888S);
    canvas->push(bg);
    bg = nullptr;

    canvas->push(animation->picture());

    //use the default fps
    if (fps > 60.0f) fps = 60.0f;   // just in case
    else if (tvg::zero(fps) || fps < 0.0f) {
        fps = (animation->totalFrame() / animation->duration());
    }

    auto delay = (1.0f / fps);
    auto transparent = bg ? false : true;

    GifWriter writer;
    if (!gifBegin(&writer, path, w, h, uint32_t(delay * 100.f))) {
        TVGERR("GIF_SAVER", "Failed gif encoding");
        return;
    }

    auto duration = animation->duration();

    for (auto p = 0.0f; p < duration; p += delay) {
        auto frameNo = animation->totalFrame() * (p / duration);
        animation->frame(frameNo);
        canvas->update();
        if (canvas->draw(true) == tvg::Result::Success) {
            canvas->sync();
        }
        if (!gifWriteFrame(&writer, reinterpret_cast<uint8_t*>(buffer), w, h, uint32_t(delay * 100.0f), transparent)) {
            TVGERR("GIF_SAVER", "Failed gif encoding");
            break;
        }
    }

    if (!gifEnd(&writer)) TVGERR("GIF_SAVER", "Failed gif encoding");
}


/************************************************************************/
/* External Class Implementation                                        */
/************************************************************************/

GifSaver::~GifSaver()
{
    close();
}


bool GifSaver::close()
{
    this->done();

    if (bg) bg->unref();
    bg = nullptr;

    //animation holds the picture, it must be 1 at the bottom.
    if (animation && animation->picture()->refCnt() <= 1) delete(animation);
    animation = nullptr;

    tvg::free(path);
    path = nullptr;

    tvg::free(buffer);
    buffer = nullptr;

    return true;
}


bool GifSaver::save(TVG_UNUSED Paint* paint, TVG_UNUSED Paint* bg, TVG_UNUSED const char* filename, TVG_UNUSED uint32_t quality)
{
    TVGLOG("GIF_SAVER", "Paint is not supported.");
    return false;
}


bool GifSaver::save(Animation* animation, Paint* bg, const char* filename, TVG_UNUSED uint32_t quality, uint32_t fps)
{
    close();

    auto picture = animation->picture();
    float x, y;
    x = y = 0;
    picture->bounds(&x, &y, &vsize[0], &vsize[1]);

    //cut off the negative space
    if (x < 0) vsize[0] += x;
    if (y < 0) vsize[1] += y;

    if (vsize[0] < FLOAT_EPSILON || vsize[1] < FLOAT_EPSILON) {
        TVGLOG("GIF_SAVER", "Saving animation(%p) has zero view size.", animation);
        return false;
    }

    if (!filename) return false;
    this->path = duplicate(filename);

    this->animation = animation;

    if (bg) {
        bg->ref();
        this->bg = bg;
    }
    this->fps = static_cast<float>(fps);

    TaskScheduler::request(this);

    return true;
}